The thermal decomposition behavior of YBCO-TFA precursors was investigated by thermogravimetric and differential scanning calorimetry analysis (TG-DSC), in-situ Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction analysis (XRD). The results show that the thermal decomposition of YBCO-TFA precursors occurred mainly in the range of 230~250 oC, and the residues were identified as BaF2, CuO, Y2O3, YBaF and other unidentified noncrystalline materials. The studies of the mechanism of thermal decomposition are beneficial to optimize the thermal decomposition processes and to achieve high critical current YBCO coated conductors